The present application relates to a method and apparatus for examining tissue for the presence of predefined target cells therein, and also to a probe for use in such method and apparatus. The invention is particularly useful for detecting cancerous cells in a real-time manner during a surgical operation for removing, e.g., a breast tumor. The invention is therefore described below with respect to such an application, but it will be appreciated that the invention is useful in many other applications.
During a surgical operation for the removal of a tumor, it would be highly desirable to provide the surgeon with a real-time indication of the nature of the tissue at the surgical site, i.e., whether it is normal tissue or cancerous tissue. In the absence of such a real-time indication, the surgeon may remove more tissue than really necessary in order to provide better assurance that the entire tumor is removed.
Existing medical instruments, such as computed tomography (CT) scanners, magnetic resonance imagining (MRI) devices, electrical bioimpedance scanning devices (T-scan), ultrasound, and other similar instruments, are commonly used in pre-operative guided biopsy procedures to obtain samples of tissues in order to delineate the extent of the cancerous tissue. However, the accuracy of such instruments and procedures for the delineation of cancerous tissue depends to a high degree on the accuracy by which the sample was taken, and the expertise of the surgeon in translating such information to the actual conditions at the tumor site.
My above-cited U.S. patent application Ser. No. 10/035,428, the contents of which are incorporated herein by reference, briefly reviews various electrical techniques described in the prior art for examining tissue in order to indicate its nature according to the dielectric properties of the examined tissue. That patent application is directed to an improved method of making such an examination, by applying an electrical pulse (or a sequence of pulses) to the tissue to be examined via a probe, which generates an electrical field in the examined tissue and produces a reflected pulse therefrom. The reflected electrical pulse is detected, and its electrical characteristics are compared with those of the applied electrical pulse to provide an indication of the dielectric properties of the examined tissue, and thereby, the extent of the presence of cancerous cells therein.
However, because of the critical importance of this information to the surgeon during a surgical operation, efforts are continually being made to provide methods, apparatus and probes, which are capable of more accurately determining the extent of the presence of cancerous cells in a real-time manner.